Proximal-type Epithelioid Sarcoma of the Head and Neck (HN): A Study with Immunohistochemical and Molecular Analysis of SMARCB1

Neck Epithelioid Sarcoma at an Unusual Location Mimicking Lymph Node Metastases of Nasopharyngeal Carcinoma: A Case Report

Epithelioid sarcoma (ES) is an uncommon soft tissue sarcoma. It is usually located in the extremities and exceptionally in the neck. Its diagnosis constitutes a real challenge which is based on histology and immunohistochemistry staining that must be interpreted with caution given the anatomopathological similarities to other tumors. In this article, we report a case of a 37-year-old man admitted for a locally advanced ES of the neck. There were suspicions of lymph node metastases of nasopharyngeal carcinoma at the first pathological examination. The patient received palliative chemotherapy and was referred to the supportive care department. Through this case, we will discuss the clinical and anatomopathological characteristics and therapeutic options of this extremely rare tumor which poses a diagnostic challenge.

Metastatic Epithelioid Sarcoma of the Eyelid in a 47-Year-Old Man: A Case Report

Epithelioid sarcoma is a rare soft tissue neoplasm of uncertain differentiation that typically affects the distal extremities. Primary orbital epithelioid sarcoma is rare, and no reports exist characterizing metastases of this tumor to the orbit and ocular adnexa. In this article, the authors describe a rare case of eyelid metastasis in a 47-year-old man with epithelioid sarcoma of the right fibula diagnosed 16 months earlier who was otherwise doing well on the adjuvant tazemetostat therapy. In addition, the authors perform a retrospective review of cases of primary orbital epithelioid sarcoma reported in the literature, of which 4 patients responded favorably to surgical excision whereas 2 others eventually died as a direct result of their disease.

Clinicopathological Characteristics, Treatment, and Survival in Patients Diagnosed With Proximal-Type Epithelioid Sarcoma: A Case Report and Systematic Review

Epithelioid sarcoma is a rare entity that shows a predilection for the young and middle-aged population. There are two subtypes, i.e., the distal or conventional type, which is located in distal extremities, and the proximal type, located in proximal areas of the extremities, pelvis, perineal, and genital region. The latter is characterized by more aggressive behavior, a higher recurrence rate, and poor prognosis. Histopathological and immunohistochemical diagnoses are key to correct and timely treatment and a higher survival rate. We report a case of a 41-year-old man who presented a palpable progressive growth mass in the hypogastrium. The disease time was of nine months, and the tumor was resected, but it recurred a few months later in the same location. Computed tomography (CT) scans showed images suggestive of lung metastasis and the patient had to undergo a second surgery. He received eight cycles of chemotherapy and a subsequent CT scan control showed the progression of the disease, so a new chemotherapy regimen was established. The patient received three cycles of chemotherapy without improvement, so he decided to discontinue treatment. His last outpatient medical consultation was in January 2022. A systematic review of the studies published in PubMed and Google Scholar was performed. We identified 291 articles, but only 41 reports and case series were included, with a total of 55 patients. It is important to include this type of tumor in the differential diagnosis of epithelial tumors due to its aggressive behavior. Correct and timely diagnosis is crucial to obtain lower recurrence rates, lower mortality, and higher survival rates in these patients.

SMARCB1/INI1-deficient tumors of adulthood

The SMARCB1/INI1 gene was first discovered in the mid-1990s, and since then it has been revealed that loss of function mutations in this gene result in aggressive rhabdoid tumors. Recently, the term "rhabdoid tumor" has become synonymous with decreased SMARCB1/INI1 expression. When genetic aberrations in the SMARCB1/INI1 gene occur, the result can cause complete loss of expression, decreased expression, and mosaic expression. Although SMARCB1/INI1-deficient tumors are predominantly sarcomas, this is a diverse group of tumors with mixed phenotypes, which can often make the diagnosis challenging. Prognosis for these aggressive tumors is often poor. Moreover, refractory and relapsing progressive disease is common. As a result, accurate and timely diagnosis is imperative. Despite the SMARCB1/INI1 gene itself and its implications in tumorigenesis being discovered over two decades ago, there is a paucity of rhabdoid tumor cases reported in the literature that detail SMARCB1/INI1 expression. Much work remains if we hope to provide additional therapeutic strategies for patients with aggressive SMARCB1/INI1-deficient tumors.

Epithelioid Sarcoma of the External Auditory Canal: An Uncommon Tumor at an Unusual Site and a Brief Overview of the Literature

We present a case (41 years old pregnant female) with epithelioid sarcoma arising in the left external auditory canal. On immunohistochemistry, the tumor cell diffusely expressed cytokeratins and showed patchy expression of ERG and CD34. The neoplastic cells demonstrated uniform loss of INI1-expression. Epithelioid sarcoma arising in the external auditory canal is rare. Awareness that ES may rarely arise at unusual sites is of critical importance in order to apply a broad enough panel in the immunohistochemical study, so a misdiagnosis of carcinoma can be avoided.

Proximal-type epithelioid sarcoma in the maxillary sinus: an unusual presentation

Epithelioid sarcoma (ES) is a rare histological type of soft tissue sarcoma presenting as a subcutaneous or deep dermal mass in the distal extremities of young adults. Recently, a more aggressive, so called 'proximal-type' ES has been described. The literature is limited on the clinical features and management of ES originating in the head and neck area. We here report a case of 16-year-old female who initially presented with progressive swelling and pain in the left cheek. On physical and radiographic examination, a malignant neoplasm was found in the left maxillary sinus with bony invasion. The definite diagnosis of proximal-type ES was based on the pathological and immunohistochemical characteristics. A subtotal maxillectomy with wide margins was performed on this patient. The patient survived uneventfully for three years. This is the first report of a proximal-type ES found in the maxillary sinus.

Epithelioid sarcoma of the scalp: a case report and literature review

Epithelioid sarcoma (ES) is an aggressive mesenchymal tumor exhibiting bi-directional phenotypes. According to its proclivity for different sites, ES can be subdivided into two categories: distal and proximal variants. Proximal ES often affects the truncal tissue, thighs, head, and neck. Accumulating evidence indicates that several locations in the head, including the orbital, gingival, and nasal cavities, are involved in ES. However, the underlying mechanisms of ES carcinogenesis and progression are largely unknown, including and especially the reason why the tumor cells are positive for both epithelial and mesenchymal classical markers. Thus, we wish to share a rare case of ES in the scalp and its clinical and molecular features. Only 9 cases to date have been reported. An 80-years-old man had sustained a painful swollen mass in his scalp for three months. A diagnosis of epithelioid sarcoma was established based on the combination of the histopathological and immunohistochemical findings. The tumor cells were positive for both mesenchymal (vimentin and S100) and epithelial markers (pan-cytokeratin). This case suggests that ES can be derived from the soft tissue of the scalp. The tumor cells co-expressed biomarkers of epithelial and mesenchymal cells, suggesting the mesenchymal-epithelial transition (MET) may be involved.

Proximal-type epithelioid sarcoma of the oral cavity: a case report and literature review

Proximal-type epithelioid sarcoma (PES) is an exceedingly rare malignant tumor of soft tissue; PES within the oral cavity is even rarer. Pathologic examination is the primary diagnostic modality, and surgical treatment is recommended as the preferred method for the treatment of PES. Currently, there is a paucity of literature that systematically reports on PES in the oral cavity. Here, we describe a 42-year-old man with PES in the oral cavity, which showed positivity for vimentin, cytokeratin, CD31, S-100 but did not express BCL-2, HMB-45, or desmin. We performed a wide excision and neck dissection, and then used the free anterolateral thigh flap to reconstruct the defect in the soft tissue. Furthermore, we review the current literature with regard to diagnosis and treatment of PES.

Clinicopathological analysis of myxoid proximal-type epithelioid sarcoma

Proximal-type epithelioid sarcoma (ES) with a diffuse myxoid stroma is rare. Here, we report the case of a 33-year-old man with a perineal mass. Imaging showed the presence of a poorly demarcated 6.9 × 5.3-cm mass in the subcutaneous perineal region. Macroscopic examination showed that the resected tissues were partially necrotic. Histological examination showed that the tumor comprised numerous large or pleomorphic epithelioid cells with large vesicular nuclei and prominent nucleoli. A clear background of necrosis and inflammatory exudates was also present. Immunohistochemical examination showed that the tumor cells were positive for vimentin and CD34 - both of which were expressed throughout the cytoplasm - but typically did not express nuclear INI1 (SMARCB1). Hematoxylin-eosin staining (HE staining) showed that the mucin content of the tumor was approximately 80%. The patient was diagnosed with proximal-type ES with myxoid features. The patient died due to disease progression after 2 months of follow-up and without undergoing further treatment in our department. To our knowledge, only 2 cases of proximal-type ES with diffuse myxoid stroma have been reported. Proximal-type ES is rare, and this is the first case report of proximal ES with myxoid features in the perineal area.

Gene of the month: SMARCB1

SMARCB1 is the core subunit of the SWI/sucrose non-fermenting ATP-dependent chromatin remodelling complex located on the long arm of chromosome 22 (22q11.2). Since discovering genetic alterations of the SMARCB1 gene in malignant rhabdoid tumours, the family of tumours harbouring loss of SMARCB1 expression has been steadily expanding. In this review, we give a general overview of SMARCB1, its role in various cancers including germline mutations, association with genetic syndromes and role in future targeted therapies.

Malignant extra-renal rhabdoid tumor with unusual presentation: A report of two cases

Malignant extra-renal rhabdoid tumor (MERT) is a rare highly aggressive tumor that occurs in young children with the very poor clinical outcome. The tumor is characterized by a diffuse proliferation of "rhabdoid cells," which are round or polygonal with eccentric nuclei, prominent nucleoli, and glassy eosinophilic cytoplasm containing hyaline-like inclusion bodies. However, rhabdoid cells are also seen in certain other soft tissue sarcomas such as proximal-type epithelioid sarcoma, rarely synovial sarcoma, and extra-skeletal myxoid chondrosarcoma. Because of its poor prognosis and histomorphological similarities with other soft tissue tumors, an accurate diagnosis is required using a wide immunohistochemical panel. Very few cases of MERT have been reported in the literature and to our knowledge none in the supra-glottis area. Due to the rarity and poor outcome of this tumor, we are reporting two cases of MERT.

The utility of ERG, CD31 and CD34 in the cytological diagnosis of angiosarcoma: an analysis of 25 cases

AIMS

Erythroblast transformation specific related gene (ERG), a proto-oncogene member of the erythroblast transformation specific transcription factor family, is a sensitive marker of endothelial differentiation and is expressed in vascular tumours, including angiosarcomas (AS). Immunohistochemistry is necessary for the diagnosis of AS in fine needle aspirates where low cellularity and lack of preserved tissue architecture impedes diagnosis. The aim of this study was to assess the utility of an ERG-enriched immunohistochemistry panel in the cytological diagnosis of AS.

METHODS

25 AS diagnosed on fine needle aspirates were stained for ERG, CD31, CD34, and AE1/AE3. Staining intensity and percentage tumour cell positivity were evaluated. Spearman's correlation was assessed for significant correlations between antibodies.

RESULTS

Sensitivities for ERG, CD31, CD34 and AE1/AE3 were 100%, 100%, 60% and 21%, respectively. Spearman's analysis revealed that ERG and CD31 staining correlated significantly; there was no significant correlation between CD31 and CD34 staining.

CONCLUSIONS

With equal sensitivity to, and strong correlation with CD31, ERG staining is highly suitable for the cytological diagnosis of AS. ERG and CD31 are more sensitive vascular markers than CD34. ERG, a nuclear stain, complements the cytoplasmic/membranous staining of CD31. Used in conjunction with CD31, ERG can corroborate the diagnosis of AS.

SMARCB1(INI1)-deficient sinonasal basaloid carcinoma: a novel member of the expanding family of SMARCB1-deficient neoplasms

Poorly differentiated sinonasal carcinomas are a heterogenous group of aggressive neoplasms that encompasses squamous cell carcinoma including basaloid variant, lymphoepithelial carcinoma, sinonasal undifferentiated carcinoma, and neuroendocrine-type small cell carcinoma. We herein describe 3 cases of a hitherto unreported variant combining features of basaloid carcinoma with variable intermingled rhabdoid cells. Patients were 2 women (aged 28 and 35) and a man (52 y) who presented with sinonasal masses. All had advanced local disease with bone involvement (pT4). None had a history of irradiation or a family history of rhabdoid tumors. Treatment was surgery and adjuvant chemoradiation. One patient developed liver, lung, pleural, and pericardial metastases (63 mo) and is currently (70 mo) alive under palliative treatment. Another developed recurrent cervical lymph node metastases and died of disease 8.5 years later. The youngest patient was disease-free at last follow-up 7 years later. Histologic features were very similar in all 3 cases and showed intimate admixture of compact basaloid cell nests with peripheral palisading, perivascular pseudorosettes, and a few scattered rhabdoid cells. Rhabdoid cells were more extensive in the metastasis in 1 case but formed a minor inconspicuous component in the primary tumors in all cases. Striking features common to all cases were (1) basaloid “blue” appearance at low power, (2) papilloma-like exophytic component, (3) extensive pagetoid surface growth with prominent denuding features, and (4) replacement of underlying mucous glands mimicking an inverted papilloma. Clear-cut origin from benign papilloma and overt squamous differentiation were lacking. Diffuse (2) or partial (1) p16 expression was noted, but all cases lacked human papillomavirus DNA by molecular tests. In situ hybridization was negative for Epstein-Barr virus. Immunohistochemistry showed diffuse expression of pancytokeratin. CK5 and vimentin showed intermingling of CK5⁺/vimentin⁻ basaloid and CK5⁻/vimentin⁺ rhabdoid cells. Complete loss of nuclear SMARCB1 expression was seen in all cases including also the denuding carcinoma in situ–like surface lesions. To our knowledge, this variant of sinonasal carcinoma has not been reported before. The identical features in all 3 cases suggest a specific disease rather than a nonspecific dedifferentiated phenotype. Awareness of this rare variant and thus reporting of additional cases is necessary for defining its full morphologic and biological spectrum.

Malignant rhabdoid tumor of the floor of mouth: first reported case in the oral cavity of an adult

Malignant rhabdoid tumors (MRTs) are exceedingly rare lesions. To our knowledge, only 2 cases have been reported in the oral cavity, with both examples occurring in infants. The current case is the third reported case of MRT of the oral cavity and the first reported case to occur in an adult at this location. The following report describes the clinical, histologic and immunohistochemical features of this tumor.